EXT-262: Fix enum name to match spec
EXT-262/EXT-154: Fix optical port properties in oflib

Tested with "dpctl port-desc" and ports set to type optical.

Verified that ofp_port with optical property can be properly
encoded and decoded, and printed.

Made changes to prevent crashes from occurring in secchan
due to TLV port messages.
EXT-154: Port stats TLV

Tested "dpctl stats-port" with optical port type and verified
that values are correctly printed.